Characterization of quorum sensing genes and N-acyl homoserine lactones in Citrobacter amalonaticus strain YG6 by Kher, Heng Leong, Krishnan, Thiba, Letchumanan, Vengadesh, Hong, Kar Wai, How, Kah Yan, Lee, Learn Han, Tee, Kok Keng, Yin, Wai Fong, Chan, Kok Gan